What is the meaning of "No man is an island"?

As humans we are part of a society, everything that we do and everything that happens to us affects not only the individual, but all of society. The fate of man will to some degree affect every other person in the world, so therefore it is in our own best interest to ensure the well being of others.

Human beings necessarily depend on one another, as if someone tells you, "You can't manage this all by yourself; no man is an island".

It is the opposite of the Bob Dylan song, I am a rock, I am an Island,...and a rock feels no pain and an Island never cries.

You get the point? We are human beings and we are made to feel emotions and made to live in a world with others as well. If you isolate yourself, you become self-centered and unhappy.

No man lives alone, each interacts with others in his life--parent(s), siblings, caregivers, co-workers, friends, even entertainers on television or radio affect our thoughts, work, philosophy, diet, etc. A farmer may work his fields alone, but he is still dependent on buyers of his crop, his seed supplier, the provider of fuel for his tractor or mule or oxen. He interacts with all of them, and to some extent, is influenced by them. Man depends on others; he is not an island, completely detached from others. Surely you can supply another example.

What we do affects others, and we all inter-react with others.